1. Field of the Invention
This invention relates to jambs and the like, such as door jambs and lintels of door frames and window frames.
2. The Problem
In first-class carpentry, it is required that door frames and window frames be made of high grade lumber, usually clear edge grain, and that the jambs and lintels each be made of one piece with the usual rib formed integral with the flange or flanges of the casing or lintel and the rib not be formed separately and nailed to the portion of the jamb or lintel forming the flange or flanges.
Such a jamb or lintel customarily is four inches (10.16 cm) to eight inches (20.32 cm) in width, and the supply of lumber from which to cut such jambs and lintels is scarce and expensive.
Conventionally, in making a jamb or lintel of T shade with a generally central rib on one side, it is necessary to rabbett the opposite edge portions of a board to form the generally central rib, and such rabbetting is very wasteful of high grade lumber.
It is common practice to veneer the face of cores to provide upgraded lumber, but veneering the face of a door jamb is difficult because of the raised rib customarily provided on jambs and lintels which forms one or two reentrant angles. Veneering the face of a jamb or lintel is particularly difficult if the edges of the rib are to be veneered.